Histological studies on the paraepiglottic tonsil of the sheep

Abstract

The paraepiglottic tonsil studied in 6 young sheep revealed stratified squamous non-keratinised epithelium having strata basale, spinosum and superficiale which modified into reticular epithelium due to heavy infiltrates of underneath lymphoid tissue. The loose irregular connective tissue of lamina propria submucosa was mainly constituted by lymphoid and glandular tissue. The lymphoid tissue organized in the form of isolated scattered aggregations and the follicles was constituted by lymphocytes, plasma cells and macrophages. The interfollicular areas were rich in lymphocytes, blood capillaries, macrophages and high endothelial venules. The mucous acini showed a strong PAS positive reaction for glycogen, acidic mucopolysaccharides and Alcianophilic mucopolysaccharides. The neutral mucopolysaccharides were localized in smaller concentration only towards the periphery of a few acini. However these reactions were absent in the glandular ducts. In addition, large venous caverns like structures filled with blood, large nerve bundles and fatty tissue were also present.